The present invention relates to a writing board to which an electronic calculator is associated and to a writing board to which an electronic calculator can be mounted.
In business situations, such as business negotiations, it is frequently necessary to take note of information from opposite party and to calculate with an electronic calculator. Thus, it is desired to provide an electronic calculator in association with a writing board. A typical example for aiming to achieve this object can be found in a memo pad case with an electronic calculator such as that described in Japanese Utility Model Laid-Open Publication No. Sho 58-194083, wherein a memo pad, a writing instrument such as a pencil or a mechanical pencil, and an electronic calculator are integrated with a case.
Meanwhile, there is known a writing board in which a microcapsule magnetic sheet is applied as a recording sheet. In this writing board, any characters and figures can be magnetically written on a top face of the recording sheet with a magnetic pen having a tip made of a magnetic material, and the characters and figures written on the top face of the recording sheet can also be erased by an erasing magnetic member which has magnetism and which is disposed adjacent to a back face of the recording sheet.
The theory of the above device will be shortly described as follows. As shown in FIG. 1, in a microcapsule magnetic sheet 10 for use in a recording sheet, microcapsules 11 respectively having about the size of 500 xcexcm in diameter are two-dimensionally arranged between a top sheet 12 and a back sheet 13. Black magnetic powders 14 having magnetism are dispersed in white emulsion 15 and encapsulated in each microcapsule 11. Thus, when magnets 16, 17 are positioned close to the microcapsule magnet sheet 10, the black magnetic powders 14 in the microcapsule 11 are magnetically attracted so as to present black color on one side of the microcapsule magnet sheet 10 to which the magnets 16, 17 are closely positioned. In contrast, on the other side of the microcapsule magnet sheet 10, white color can be presented due to only presence of the. white emulsion 15. In the writing board applying the microcapsule magnetic sheet as the recording sheet, by utilizing the above theory of magneticphoresis, black color characters or figures can be freely written on the top sheet 12 with the magnet 16. In addition, when the magnet 17 is positioned close to and moved along the back sheet 13 of the microcapsule magnetic sheet 10, the magnetic powders 14 in the microcapsule 11 are attracted along the track of the magnet 17 toward the back sheet 13, so that the characters or figures written on the front sheet 12 can be erased.
The aforementioned writing board provided with an electronic calculator involves the burden of appropriately supplementing a memo pad and a writing instrument and of disposing used memo papers. Further, when it is required to operate the electronic calculator, a user is required to actuate keys of the electronic calculator after putting off a pen from his hand so as not to stain the electronic calculator, hands or the like. Thus, handling is also burdensome.
Thus, it may be appreciated to apply the writing board with the aforementioned microcapsule magnetic sheet as a writing board which is to be combined with an electronic calculator, so as to make it possible to repeatedly write and erase without consuming any memo pad and writing instrument, and without staining the electronic calculator, hands or the like.
However, the conventional microcapsule magnetic sheet type writing board has a problem that a burdensome operation is necessary for erasing writings on the recording sheet. Thus, utilizing this kind of writing board in combination with an electronic calculator does not always provide a device which is convenient to use.
It is an object of the present invention to solve the aforementioned problems in using a microcapsule magnetic sheet type writing board in combination with an electronic calculator. Another object of the present invention is to provide a novel structure for a writing board with an electronic calculator and a writing board to which an electronic calculator can be mounted. A further object of the present invention is to provide a writing board wherein no supplement of memo pads and writing instruments are required, no operation being required for disposing of used memo papers. A further object of the present invention is to provide a writing board wherein keys of the calculator can be pushed by a finger of a hand holding a pen or by an end or tip of the pen without risk of staining the electronic calculator, hands or the like. Still further object of the present invention is to provide a writing board including a microcapsule magnetic sheet but writings on the sheet can be easily erased.
In order to achieve the above and other objects, a writing board with an electronic calculator according to the present invention, comprises a case member provide with an opening in a top surface of the case member and having a frame section surrounding the opening in the top surface of the case member, a recording sheet which is comprised of a microcapsule magnetic sheet and disposed in the case member with a top face of the recording sheet exposed through the opening of the case member, a magnetic member for writing on the recording sheet, a magnetic erasing sheet which is positioned under the recording sheet in parallel with the recording sheet, an erasing button provided in the case member, and an electronic calculator disposed on the top surface of the case member, wherein the erasing sheet is connected to a driving device powered by a motor, the driving device being adapted to drive the erasing sheet to erase writings on the recording sheet by reciprocating the erasing sheet while maintaining the erasing sheet substantially in parallel with the recording sheet, from a position where the erasing sheet is far enough from the recording sheet so that the magnetic force of erasing sheet may not erase the writings on the recording sheet, to a position where the erasing sheet is close enough to the recording sheet so that the erasing sheet can apply a magnetic influence on the recording sheet to thereby erase writings on the recording sheet, the driving device being provided with a switching device which is associated with the erasing button and adapted to be turned on by depressing the erasing button. The switching device is so constructed that, once it is turned on, it is maintained in on state until the erasing sheet finishes one cycle of reciprocating motion, and to be turned off when the erasing sheet finishes the one cycle of reciprocating motion.